Project Summary/Abstract The aim of this project is to develop a novel `liquid array' platform, based on Encoded Sortable Particle (ESP) technology. ESPs are optically-encoded microfabricated particles that can be manipulated using magnetic force. They are manufactured on commercially available photolithographic equipment using efficient and robust techniques borrowed from the semi-conductor industry. They have significant advantages in cost throughput, scalability, and flexibility over existing bead-based liquid array platforms. We will develop a liquid array system that can accommodate multiplexing levels of 1000-plex or more, and that will be more flexible and easier to use than existing systems. Its design will also permit substantially lower capital and running costs and similar or better quantitative performance, including precision, limit of detection and dynamic range.